class_docstr: The multi dimensional Brownian Motion.
class_docstr_tok: ["The","multi","dimensional","Brownian","Motion","."]
code: def volatility_fn(self):
      return lambda t, x: self._volatility_fn(t)
  
file_path: tf-quant-finance/tf_quant_finance/models/legacy/brownian_motion.py
imports: import tensorflow.compat.v2
  from tf_quant_finance.math.random_ops import multivariate_normal
  from tf_quant_finance.models.legacy import brownian_motion_utils
  from tf_quant_finance.models.legacy import ito_process
label_desc: Use image node_id 6 for calling the BrownianMotion obj's underlying member method code with example usage: obj.volatility_fn() and returns: function